While it is not necessary to calibrate the Kevo fob, it is recommended to do so for enhanced security purposes.
If the calibration results in a red flashing light ring at the end of the third touch sequence, then a poor calibration was performed. This could be due to where you are carrying your Smartphone/Kevo fob. You can accept a poor calibration, however accepting a poor calibration is not advised and could cause Kevo to be susceptible to unauthorized operation while your Smartphone/Kevo fob is inside of your home. If you continue to have calibration issues, call Kevo support.